The gripper of a manipulator provides a general purpose handling facility for tasks such as lifting, transporting, orienting and holding work pieces or tools which in turn perform special operations on work pieces. Because of the variety of operations and variety of shapes of objects to be handled by the gripper of the manipulator, the gripper finger pads or tools are not always suitable for a particular component to be handled or operation to be performed. Accordingly, after a cycle of operation, when a different sized component or shaped component or tool is to be handled, the gripper pads or tools are changed manually. It should be appreciated that this requires a considerable time interruption of the operation of the manipulator and in some cases requires considerable down time of the manipulator to make the change. In order to prevent operation interruptions, the gripper pad or tool has been designed such that it is capable of handling different shaped components. Such an all-inclusive design results in poor quality holding and handling of parts and in some instances introduces errors or inaccuracies.
In view of today's high speed manipulators and minimal grasping forces to prevent crushing of fragile components carried thereby, and also in view of the heavy weight objects carried thereby, it is felt necessary, if for no other reason than safety, to provide a locking means for securing the finger tools fixedly in place on the manipulator gripper. Furthermore, means of monitoring the desired locked position of the finger tool on the gripper to provide an indication of when the pad or tool is missing or is not securely locked in place is needed.